| //! The `SourceMap` tracks all the source code used within a single crate, mapping |
| //! from integer byte positions to the original source code location. Each bit |
| //! of source parsed during crate parsing (typically files, in-memory strings, |
| //! or various bits of macro expansion) cover a continuous range of bytes in the |
| //! `SourceMap` and are represented by `SourceFile`s. Byte positions are stored in |
| //! `Span` and used pervasively in the compiler. They are absolute positions |
| //! within the `SourceMap`, which upon request can be converted to line and column |
| //! information, source code snippets, etc. |
| |
| pub use crate::*; |
| pub use crate::hygiene::{ExpnKind, ExpnData}; |
| |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_data_structures::stable_hasher::StableHasher; |
| use rustc_data_structures::sync::{Lrc, Lock, LockGuard, MappedLockGuard}; |
| use std::cmp; |
| use std::hash::Hash; |
| use std::path::{Path, PathBuf}; |
| |
| use std::env; |
| use std::fs; |
| use std::io; |
| use log::debug; |
| |
| #[cfg(test)] |
| mod tests; |
| |
| /// Returns the span itself if it doesn't come from a macro expansion, |
| /// otherwise return the call site span up to the `enclosing_sp` by |
| /// following the `expn_data` chain. |
| pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span { |
| let expn_data1 = sp.ctxt().outer_expn_data(); |
| let expn_data2 = enclosing_sp.ctxt().outer_expn_data(); |
| if expn_data1.is_root() || |
| !expn_data2.is_root() && expn_data1.call_site == expn_data2.call_site { |
| sp |
| } else { |
| original_sp(expn_data1.call_site, enclosing_sp) |
| } |
| } |
| |
| #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, HashStable_Generic)] |
| pub struct Spanned<T> { |
| pub node: T, |
| pub span: Span, |
| } |
| |
| pub fn respan<T>(sp: Span, t: T) -> Spanned<T> { |
| Spanned {node: t, span: sp} |
| } |
| |
| pub fn dummy_spanned<T>(t: T) -> Spanned<T> { |
| respan(DUMMY_SP, t) |
| } |
| |
| // _____________________________________________________________________________ |
| // SourceFile, MultiByteChar, FileName, FileLines |
| // |
| |
| /// An abstraction over the fs operations used by the Parser. |
| pub trait FileLoader { |
| /// Query the existence of a file. |
| fn file_exists(&self, path: &Path) -> bool; |
| |
| /// Returns an absolute path to a file, if possible. |
| fn abs_path(&self, path: &Path) -> Option<PathBuf>; |
| |
| /// Read the contents of an UTF-8 file into memory. |
| fn read_file(&self, path: &Path) -> io::Result<String>; |
| } |
| |
| /// A FileLoader that uses std::fs to load real files. |
| pub struct RealFileLoader; |
| |
| impl FileLoader for RealFileLoader { |
| fn file_exists(&self, path: &Path) -> bool { |
| fs::metadata(path).is_ok() |
| } |
| |
| fn abs_path(&self, path: &Path) -> Option<PathBuf> { |
| if path.is_absolute() { |
| Some(path.to_path_buf()) |
| } else { |
| env::current_dir() |
| .ok() |
| .map(|cwd| cwd.join(path)) |
| } |
| } |
| |
| fn read_file(&self, path: &Path) -> io::Result<String> { |
| fs::read_to_string(path) |
| } |
| } |
| |
| // This is a `SourceFile` identifier that is used to correlate `SourceFile`s between |
| // subsequent compilation sessions (which is something we need to do during |
| // incremental compilation). |
| #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)] |
| pub struct StableSourceFileId(u128); |
| |
| impl StableSourceFileId { |
| pub fn new(source_file: &SourceFile) -> StableSourceFileId { |
| StableSourceFileId::new_from_pieces(&source_file.name, |
| source_file.name_was_remapped, |
| source_file.unmapped_path.as_ref()) |
| } |
| |
| pub fn new_from_pieces(name: &FileName, |
| name_was_remapped: bool, |
| unmapped_path: Option<&FileName>) -> StableSourceFileId { |
| let mut hasher = StableHasher::new(); |
| |
| name.hash(&mut hasher); |
| name_was_remapped.hash(&mut hasher); |
| unmapped_path.hash(&mut hasher); |
| |
| StableSourceFileId(hasher.finish()) |
| } |
| } |
| |
| // _____________________________________________________________________________ |
| // SourceMap |
| // |
| |
| #[derive(Default)] |
| pub(super) struct SourceMapFiles { |
| source_files: Vec<Lrc<SourceFile>>, |
| stable_id_to_source_file: FxHashMap<StableSourceFileId, Lrc<SourceFile>> |
| } |
| |
| pub struct SourceMap { |
| files: Lock<SourceMapFiles>, |
| file_loader: Box<dyn FileLoader + Sync + Send>, |
| // This is used to apply the file path remapping as specified via |
| // `--remap-path-prefix` to all `SourceFile`s allocated within this `SourceMap`. |
| path_mapping: FilePathMapping, |
| } |
| |
| impl SourceMap { |
| pub fn new(path_mapping: FilePathMapping) -> SourceMap { |
| SourceMap { |
| files: Default::default(), |
| file_loader: Box::new(RealFileLoader), |
| path_mapping, |
| } |
| } |
| |
| pub fn with_file_loader(file_loader: Box<dyn FileLoader + Sync + Send>, |
| path_mapping: FilePathMapping) |
| -> SourceMap { |
| SourceMap { |
| files: Default::default(), |
| file_loader, |
| path_mapping, |
| } |
| } |
| |
| pub fn path_mapping(&self) -> &FilePathMapping { |
| &self.path_mapping |
| } |
| |
| pub fn file_exists(&self, path: &Path) -> bool { |
| self.file_loader.file_exists(path) |
| } |
| |
| pub fn load_file(&self, path: &Path) -> io::Result<Lrc<SourceFile>> { |
| let src = self.file_loader.read_file(path)?; |
| let filename = path.to_owned().into(); |
| Ok(self.new_source_file(filename, src)) |
| } |
| |
| /// Loads source file as a binary blob. |
| /// |
| /// Unlike `load_file`, guarantees that no normalization like BOM-removal |
| /// takes place. |
| pub fn load_binary_file(&self, path: &Path) -> io::Result<Vec<u8>> { |
| // Ideally, this should use `self.file_loader`, but it can't |
| // deal with binary files yet. |
| let bytes = fs::read(path)?; |
| |
| // We need to add file to the `SourceMap`, so that it is present |
| // in dep-info. There's also an edge case that file might be both |
| // loaded as a binary via `include_bytes!` and as proper `SourceFile` |
| // via `mod`, so we try to use real file contents and not just an |
| // empty string. |
| let text = std::str::from_utf8(&bytes).unwrap_or("") |
| .to_string(); |
| self.new_source_file(path.to_owned().into(), text); |
| Ok(bytes) |
| } |
| |
| pub fn files(&self) -> MappedLockGuard<'_, Vec<Lrc<SourceFile>>> { |
| LockGuard::map(self.files.borrow(), |files| &mut files.source_files) |
| } |
| |
| pub fn source_file_by_stable_id(&self, stable_id: StableSourceFileId) -> |
| Option<Lrc<SourceFile>> { |
| self.files.borrow().stable_id_to_source_file.get(&stable_id).map(|sf| sf.clone()) |
| } |
| |
| fn next_start_pos(&self) -> usize { |
| match self.files.borrow().source_files.last() { |
| None => 0, |
| // Add one so there is some space between files. This lets us distinguish |
| // positions in the `SourceMap`, even in the presence of zero-length files. |
| Some(last) => last.end_pos.to_usize() + 1, |
| } |
| } |
| |
| /// Creates a new `SourceFile`. |
| /// If a file already exists in the `SourceMap` with the same ID, that file is returned |
| /// unmodified. |
| pub fn new_source_file(&self, filename: FileName, src: String) -> Lrc<SourceFile> { |
| self.try_new_source_file(filename, src) |
| .unwrap_or_else(|OffsetOverflowError| { |
| eprintln!("fatal error: rustc does not support files larger than 4GB"); |
| crate::fatal_error::FatalError.raise() |
| }) |
| } |
| |
| fn try_new_source_file( |
| &self, |
| filename: FileName, |
| src: String |
| ) -> Result<Lrc<SourceFile>, OffsetOverflowError> { |
| let start_pos = self.next_start_pos(); |
| |
| // The path is used to determine the directory for loading submodules and |
| // include files, so it must be before remapping. |
| // Note that filename may not be a valid path, eg it may be `<anon>` etc, |
| // but this is okay because the directory determined by `path.pop()` will |
| // be empty, so the working directory will be used. |
| let unmapped_path = filename.clone(); |
| |
| let (filename, was_remapped) = match filename { |
| FileName::Real(filename) => { |
| let (filename, was_remapped) = self.path_mapping.map_prefix(filename); |
| (FileName::Real(filename), was_remapped) |
| }, |
| other => (other, false), |
| }; |
| |
| let file_id = StableSourceFileId::new_from_pieces(&filename, |
| was_remapped, |
| Some(&unmapped_path)); |
| |
| let lrc_sf = match self.source_file_by_stable_id(file_id) { |
| Some(lrc_sf) => lrc_sf, |
| None => { |
| let source_file = Lrc::new(SourceFile::new( |
| filename, |
| was_remapped, |
| unmapped_path, |
| src, |
| Pos::from_usize(start_pos), |
| )?); |
| |
| let mut files = self.files.borrow_mut(); |
| |
| files.source_files.push(source_file.clone()); |
| files.stable_id_to_source_file.insert(file_id, source_file.clone()); |
| |
| source_file |
| } |
| }; |
| Ok(lrc_sf) |
| } |
| |
| /// Allocates a new `SourceFile` representing a source file from an external |
| /// crate. The source code of such an "imported `SourceFile`" is not available, |
| /// but we still know enough to generate accurate debuginfo location |
| /// information for things inlined from other crates. |
| pub fn new_imported_source_file( |
| &self, |
| filename: FileName, |
| name_was_remapped: bool, |
| crate_of_origin: u32, |
| src_hash: u128, |
| name_hash: u128, |
| source_len: usize, |
| mut file_local_lines: Vec<BytePos>, |
| mut file_local_multibyte_chars: Vec<MultiByteChar>, |
| mut file_local_non_narrow_chars: Vec<NonNarrowChar>, |
| mut file_local_normalized_pos: Vec<NormalizedPos>, |
| ) -> Lrc<SourceFile> { |
| let start_pos = self.next_start_pos(); |
| |
| let end_pos = Pos::from_usize(start_pos + source_len); |
| let start_pos = Pos::from_usize(start_pos); |
| |
| for pos in &mut file_local_lines { |
| *pos = *pos + start_pos; |
| } |
| |
| for mbc in &mut file_local_multibyte_chars { |
| mbc.pos = mbc.pos + start_pos; |
| } |
| |
| for swc in &mut file_local_non_narrow_chars { |
| *swc = *swc + start_pos; |
| } |
| |
| for nc in &mut file_local_normalized_pos { |
| nc.pos = nc.pos + start_pos; |
| } |
| |
| let source_file = Lrc::new(SourceFile { |
| name: filename, |
| name_was_remapped, |
| unmapped_path: None, |
| crate_of_origin, |
| src: None, |
| src_hash, |
| external_src: Lock::new(ExternalSource::AbsentOk), |
| start_pos, |
| end_pos, |
| lines: file_local_lines, |
| multibyte_chars: file_local_multibyte_chars, |
| non_narrow_chars: file_local_non_narrow_chars, |
| normalized_pos: file_local_normalized_pos, |
| name_hash, |
| }); |
| |
| let mut files = self.files.borrow_mut(); |
| |
| files.source_files.push(source_file.clone()); |
| files.stable_id_to_source_file.insert(StableSourceFileId::new(&source_file), |
| source_file.clone()); |
| |
| source_file |
| } |
| |
| pub fn mk_substr_filename(&self, sp: Span) -> String { |
| let pos = self.lookup_char_pos(sp.lo()); |
| format!("<{}:{}:{}>", |
| pos.file.name, |
| pos.line, |
| pos.col.to_usize() + 1) |
| } |
| |
| // If there is a doctest offset, applies it to the line. |
| pub fn doctest_offset_line(&self, file: &FileName, orig: usize) -> usize { |
| return match file { |
| FileName::DocTest(_, offset) => { |
| return if *offset >= 0 { |
| orig + *offset as usize |
| } else { |
| orig - (-(*offset)) as usize |
| } |
| }, |
| _ => orig |
| } |
| } |
| |
| /// Looks up source information about a `BytePos`. |
| pub fn lookup_char_pos(&self, pos: BytePos) -> Loc { |
| let chpos = self.bytepos_to_file_charpos(pos); |
| match self.lookup_line(pos) { |
| Ok(SourceFileAndLine { sf: f, line: a }) => { |
| let line = a + 1; // Line numbers start at 1 |
| let linebpos = f.lines[a]; |
| let linechpos = self.bytepos_to_file_charpos(linebpos); |
| let col = chpos - linechpos; |
| |
| let col_display = { |
| let start_width_idx = f |
| .non_narrow_chars |
| .binary_search_by_key(&linebpos, |x| x.pos()) |
| .unwrap_or_else(|x| x); |
| let end_width_idx = f |
| .non_narrow_chars |
| .binary_search_by_key(&pos, |x| x.pos()) |
| .unwrap_or_else(|x| x); |
| let special_chars = end_width_idx - start_width_idx; |
| let non_narrow: usize = f |
| .non_narrow_chars[start_width_idx..end_width_idx] |
| .into_iter() |
| .map(|x| x.width()) |
| .sum(); |
| col.0 - special_chars + non_narrow |
| }; |
| debug!("byte pos {:?} is on the line at byte pos {:?}", |
| pos, linebpos); |
| debug!("char pos {:?} is on the line at char pos {:?}", |
| chpos, linechpos); |
| debug!("byte is on line: {}", line); |
| assert!(chpos >= linechpos); |
| Loc { |
| file: f, |
| line, |
| col, |
| col_display, |
| } |
| } |
| Err(f) => { |
| let col_display = { |
| let end_width_idx = f |
| .non_narrow_chars |
| .binary_search_by_key(&pos, |x| x.pos()) |
| .unwrap_or_else(|x| x); |
| let non_narrow: usize = f |
| .non_narrow_chars[0..end_width_idx] |
| .into_iter() |
| .map(|x| x.width()) |
| .sum(); |
| chpos.0 - end_width_idx + non_narrow |
| }; |
| Loc { |
| file: f, |
| line: 0, |
| col: chpos, |
| col_display, |
| } |
| } |
| } |
| } |
| |
| // If the corresponding `SourceFile` is empty, does not return a line number. |
| pub fn lookup_line(&self, pos: BytePos) -> Result<SourceFileAndLine, Lrc<SourceFile>> { |
| let idx = self.lookup_source_file_idx(pos); |
| |
| let f = (*self.files.borrow().source_files)[idx].clone(); |
| |
| match f.lookup_line(pos) { |
| Some(line) => Ok(SourceFileAndLine { sf: f, line }), |
| None => Err(f) |
| } |
| } |
| |
| /// Returns `Some(span)`, a union of the LHS and RHS span. The LHS must precede the RHS. If |
| /// there are gaps between LHS and RHS, the resulting union will cross these gaps. |
| /// For this to work, |
| /// |
| /// * the syntax contexts of both spans much match, |
| /// * the LHS span needs to end on the same line the RHS span begins, |
| /// * the LHS span must start at or before the RHS span. |
| pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> { |
| // Ensure we're at the same expansion ID. |
| if sp_lhs.ctxt() != sp_rhs.ctxt() { |
| return None; |
| } |
| |
| let lhs_end = match self.lookup_line(sp_lhs.hi()) { |
| Ok(x) => x, |
| Err(_) => return None |
| }; |
| let rhs_begin = match self.lookup_line(sp_rhs.lo()) { |
| Ok(x) => x, |
| Err(_) => return None |
| }; |
| |
| // If we must cross lines to merge, don't merge. |
| if lhs_end.line != rhs_begin.line { |
| return None; |
| } |
| |
| // Ensure these follow the expected order and that we don't overlap. |
| if (sp_lhs.lo() <= sp_rhs.lo()) && (sp_lhs.hi() <= sp_rhs.lo()) { |
| Some(sp_lhs.to(sp_rhs)) |
| } else { |
| None |
| } |
| } |
| |
| pub fn span_to_string(&self, sp: Span) -> String { |
| if self.files.borrow().source_files.is_empty() && sp.is_dummy() { |
| return "no-location".to_string(); |
| } |
| |
| let lo = self.lookup_char_pos(sp.lo()); |
| let hi = self.lookup_char_pos(sp.hi()); |
| format!("{}:{}:{}: {}:{}", |
| lo.file.name, |
| lo.line, |
| lo.col.to_usize() + 1, |
| hi.line, |
| hi.col.to_usize() + 1, |
| ) |
| } |
| |
| pub fn span_to_filename(&self, sp: Span) -> FileName { |
| self.lookup_char_pos(sp.lo()).file.name.clone() |
| } |
| |
| pub fn span_to_unmapped_path(&self, sp: Span) -> FileName { |
| self.lookup_char_pos(sp.lo()).file.unmapped_path.clone() |
| .expect("`SourceMap::span_to_unmapped_path` called for imported `SourceFile`?") |
| } |
| |
| pub fn is_multiline(&self, sp: Span) -> bool { |
| let lo = self.lookup_char_pos(sp.lo()); |
| let hi = self.lookup_char_pos(sp.hi()); |
| lo.line != hi.line |
| } |
| |
| pub fn span_to_lines(&self, sp: Span) -> FileLinesResult { |
| debug!("span_to_lines(sp={:?})", sp); |
| |
| let lo = self.lookup_char_pos(sp.lo()); |
| debug!("span_to_lines: lo={:?}", lo); |
| let hi = self.lookup_char_pos(sp.hi()); |
| debug!("span_to_lines: hi={:?}", hi); |
| |
| if lo.file.start_pos != hi.file.start_pos { |
| return Err(SpanLinesError::DistinctSources(DistinctSources { |
| begin: (lo.file.name.clone(), lo.file.start_pos), |
| end: (hi.file.name.clone(), hi.file.start_pos), |
| })); |
| } |
| assert!(hi.line >= lo.line); |
| |
| let mut lines = Vec::with_capacity(hi.line - lo.line + 1); |
| |
| // The span starts partway through the first line, |
| // but after that it starts from offset 0. |
| let mut start_col = lo.col; |
| |
| // For every line but the last, it extends from `start_col` |
| // and to the end of the line. Be careful because the line |
| // numbers in Loc are 1-based, so we subtract 1 to get 0-based |
| // lines. |
| for line_index in lo.line-1 .. hi.line-1 { |
| let line_len = lo.file.get_line(line_index) |
| .map(|s| s.chars().count()) |
| .unwrap_or(0); |
| lines.push(LineInfo { line_index, |
| start_col, |
| end_col: CharPos::from_usize(line_len) }); |
| start_col = CharPos::from_usize(0); |
| } |
| |
| // For the last line, it extends from `start_col` to `hi.col`: |
| lines.push(LineInfo { line_index: hi.line - 1, |
| start_col, |
| end_col: hi.col }); |
| |
| Ok(FileLines {file: lo.file, lines}) |
| } |
| |
| /// Extracts the source surrounding the given `Span` using the `extract_source` function. The |
| /// extract function takes three arguments: a string slice containing the source, an index in |
| /// the slice for the beginning of the span and an index in the slice for the end of the span. |
| fn span_to_source<F>(&self, sp: Span, extract_source: F) -> Result<String, SpanSnippetError> |
| where F: Fn(&str, usize, usize) -> Result<String, SpanSnippetError> |
| { |
| let local_begin = self.lookup_byte_offset(sp.lo()); |
| let local_end = self.lookup_byte_offset(sp.hi()); |
| |
| if local_begin.sf.start_pos != local_end.sf.start_pos { |
| return Err(SpanSnippetError::DistinctSources(DistinctSources { |
| begin: (local_begin.sf.name.clone(), |
| local_begin.sf.start_pos), |
| end: (local_end.sf.name.clone(), |
| local_end.sf.start_pos) |
| })); |
| } else { |
| self.ensure_source_file_source_present(local_begin.sf.clone()); |
| |
| let start_index = local_begin.pos.to_usize(); |
| let end_index = local_end.pos.to_usize(); |
| let source_len = (local_begin.sf.end_pos - |
| local_begin.sf.start_pos).to_usize(); |
| |
| if start_index > end_index || end_index > source_len { |
| return Err(SpanSnippetError::MalformedForSourcemap( |
| MalformedSourceMapPositions { |
| name: local_begin.sf.name.clone(), |
| source_len, |
| begin_pos: local_begin.pos, |
| end_pos: local_end.pos, |
| })); |
| } |
| |
| if let Some(ref src) = local_begin.sf.src { |
| return extract_source(src, start_index, end_index); |
| } else if let Some(src) = local_begin.sf.external_src.borrow().get_source() { |
| return extract_source(src, start_index, end_index); |
| } else { |
| return Err(SpanSnippetError::SourceNotAvailable { |
| filename: local_begin.sf.name.clone() |
| }); |
| } |
| } |
| } |
| |
| /// Returns the source snippet as `String` corresponding to the given `Span`. |
| pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> { |
| self.span_to_source(sp, |src, start_index, end_index| src.get(start_index..end_index) |
| .map(|s| s.to_string()) |
| .ok_or_else(|| SpanSnippetError::IllFormedSpan(sp))) |
| } |
| |
| pub fn span_to_margin(&self, sp: Span) -> Option<usize> { |
| match self.span_to_prev_source(sp) { |
| Err(_) => None, |
| Ok(source) => source.split('\n').last().map(|last_line| { |
| last_line.len() - last_line.trim_start().len() |
| }) |
| } |
| } |
| |
| /// Returns the source snippet as `String` before the given `Span`. |
| pub fn span_to_prev_source(&self, sp: Span) -> Result<String, SpanSnippetError> { |
| self.span_to_source(sp, |src, start_index, _| src.get(..start_index) |
| .map(|s| s.to_string()) |
| .ok_or_else(|| SpanSnippetError::IllFormedSpan(sp))) |
| } |
| |
| /// Extends the given `Span` to just after the previous occurrence of `c`. Return the same span |
| /// if no character could be found or if an error occurred while retrieving the code snippet. |
| pub fn span_extend_to_prev_char(&self, sp: Span, c: char) -> Span { |
| if let Ok(prev_source) = self.span_to_prev_source(sp) { |
| let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_start(); |
| if !prev_source.is_empty() && !prev_source.contains('\n') { |
| return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32)); |
| } |
| } |
| |
| sp |
| } |
| |
| /// Extends the given `Span` to just after the previous occurrence of `pat` when surrounded by |
| /// whitespace. Returns the same span if no character could be found or if an error occurred |
| /// while retrieving the code snippet. |
| pub fn span_extend_to_prev_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span { |
| // assure that the pattern is delimited, to avoid the following |
| // fn my_fn() |
| // ^^^^ returned span without the check |
| // ---------- correct span |
| for ws in &[" ", "\t", "\n"] { |
| let pat = pat.to_owned() + ws; |
| if let Ok(prev_source) = self.span_to_prev_source(sp) { |
| let prev_source = prev_source.rsplit(&pat).nth(0).unwrap_or("").trim_start(); |
| if !prev_source.is_empty() && (!prev_source.contains('\n') || accept_newlines) { |
| return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32)); |
| } |
| } |
| } |
| |
| sp |
| } |
| |
| /// Given a `Span`, tries to get a shorter span ending before the first occurrence of `char` |
| /// `c`. |
| pub fn span_until_char(&self, sp: Span, c: char) -> Span { |
| match self.span_to_snippet(sp) { |
| Ok(snippet) => { |
| let snippet = snippet.split(c).nth(0).unwrap_or("").trim_end(); |
| if !snippet.is_empty() && !snippet.contains('\n') { |
| sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32)) |
| } else { |
| sp |
| } |
| } |
| _ => sp, |
| } |
| } |
| |
| /// Given a `Span`, tries to get a shorter span ending just after the first occurrence of `char` |
| /// `c`. |
| pub fn span_through_char(&self, sp: Span, c: char) -> Span { |
| if let Ok(snippet) = self.span_to_snippet(sp) { |
| if let Some(offset) = snippet.find(c) { |
| return sp.with_hi(BytePos(sp.lo().0 + (offset + c.len_utf8()) as u32)); |
| } |
| } |
| sp |
| } |
| |
| /// Given a `Span`, gets a new `Span` covering the first token and all its trailing whitespace |
| /// or the original `Span`. |
| /// |
| /// If `sp` points to `"let mut x"`, then a span pointing at `"let "` will be returned. |
| pub fn span_until_non_whitespace(&self, sp: Span) -> Span { |
| let mut whitespace_found = false; |
| |
| self.span_take_while(sp, |c| { |
| if !whitespace_found && c.is_whitespace() { |
| whitespace_found = true; |
| } |
| |
| if whitespace_found && !c.is_whitespace() { |
| false |
| } else { |
| true |
| } |
| }) |
| } |
| |
| /// Given a `Span`, gets a new `Span` covering the first token without its trailing whitespace |
| /// or the original `Span` in case of error. |
| /// |
| /// If `sp` points to `"let mut x"`, then a span pointing at `"let"` will be returned. |
| pub fn span_until_whitespace(&self, sp: Span) -> Span { |
| self.span_take_while(sp, |c| !c.is_whitespace()) |
| } |
| |
| /// Given a `Span`, gets a shorter one until `predicate` yields `false`. |
| pub fn span_take_while<P>(&self, sp: Span, predicate: P) -> Span |
| where P: for <'r> FnMut(&'r char) -> bool |
| { |
| if let Ok(snippet) = self.span_to_snippet(sp) { |
| let offset = snippet.chars() |
| .take_while(predicate) |
| .map(|c| c.len_utf8()) |
| .sum::<usize>(); |
| |
| sp.with_hi(BytePos(sp.lo().0 + (offset as u32))) |
| } else { |
| sp |
| } |
| } |
| |
| pub fn def_span(&self, sp: Span) -> Span { |
| self.span_until_char(sp, '{') |
| } |
| |
| /// Returns a new span representing just the start point of this span. |
| pub fn start_point(&self, sp: Span) -> Span { |
| let pos = sp.lo().0; |
| let width = self.find_width_of_character_at_span(sp, false); |
| let corrected_start_position = pos.checked_add(width).unwrap_or(pos); |
| let end_point = BytePos(cmp::max(corrected_start_position, sp.lo().0)); |
| sp.with_hi(end_point) |
| } |
| |
| /// Returns a new span representing just the end point of this span. |
| pub fn end_point(&self, sp: Span) -> Span { |
| let pos = sp.hi().0; |
| |
| let width = self.find_width_of_character_at_span(sp, false); |
| let corrected_end_position = pos.checked_sub(width).unwrap_or(pos); |
| |
| let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0)); |
| sp.with_lo(end_point) |
| } |
| |
| /// Returns a new span representing the next character after the end-point of this span. |
| pub fn next_point(&self, sp: Span) -> Span { |
| let start_of_next_point = sp.hi().0; |
| |
| let width = self.find_width_of_character_at_span(sp, true); |
| // If the width is 1, then the next span should point to the same `lo` and `hi`. However, |
| // in the case of a multibyte character, where the width != 1, the next span should |
| // span multiple bytes to include the whole character. |
| let end_of_next_point = start_of_next_point.checked_add( |
| width - 1).unwrap_or(start_of_next_point); |
| |
| let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point)); |
| Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt()) |
| } |
| |
| /// Finds the width of a character, either before or after the provided span. |
| fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 { |
| let sp = sp.data(); |
| if sp.lo == sp.hi { |
| debug!("find_width_of_character_at_span: early return empty span"); |
| return 1; |
| } |
| |
| let local_begin = self.lookup_byte_offset(sp.lo); |
| let local_end = self.lookup_byte_offset(sp.hi); |
| debug!("find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`", |
| local_begin, local_end); |
| |
| if local_begin.sf.start_pos != local_end.sf.start_pos { |
| debug!("find_width_of_character_at_span: begin and end are in different files"); |
| return 1; |
| } |
| |
| let start_index = local_begin.pos.to_usize(); |
| let end_index = local_end.pos.to_usize(); |
| debug!("find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`", |
| start_index, end_index); |
| |
| // Disregard indexes that are at the start or end of their spans, they can't fit bigger |
| // characters. |
| if (!forwards && end_index == usize::min_value()) || |
| (forwards && start_index == usize::max_value()) { |
| debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte"); |
| return 1; |
| } |
| |
| let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).to_usize(); |
| debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len); |
| // Ensure indexes are also not malformed. |
| if start_index > end_index || end_index > source_len { |
| debug!("find_width_of_character_at_span: source indexes are malformed"); |
| return 1; |
| } |
| |
| let src = local_begin.sf.external_src.borrow(); |
| |
| // We need to extend the snippet to the end of the src rather than to end_index so when |
| // searching forwards for boundaries we've got somewhere to search. |
| let snippet = if let Some(ref src) = local_begin.sf.src { |
| let len = src.len(); |
| (&src[start_index..len]) |
| } else if let Some(src) = src.get_source() { |
| let len = src.len(); |
| (&src[start_index..len]) |
| } else { |
| return 1; |
| }; |
| debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet); |
| |
| let mut target = if forwards { end_index + 1 } else { end_index - 1 }; |
| debug!("find_width_of_character_at_span: initial target=`{:?}`", target); |
| |
| while !snippet.is_char_boundary(target - start_index) && target < source_len { |
| target = if forwards { |
| target + 1 |
| } else { |
| match target.checked_sub(1) { |
| Some(target) => target, |
| None => { |
| break; |
| } |
| } |
| }; |
| debug!("find_width_of_character_at_span: target=`{:?}`", target); |
| } |
| debug!("find_width_of_character_at_span: final target=`{:?}`", target); |
| |
| if forwards { |
| (target - end_index) as u32 |
| } else { |
| (end_index - target) as u32 |
| } |
| } |
| |
| pub fn get_source_file(&self, filename: &FileName) -> Option<Lrc<SourceFile>> { |
| for sf in self.files.borrow().source_files.iter() { |
| if *filename == sf.name { |
| return Some(sf.clone()); |
| } |
| } |
| None |
| } |
| |
| /// For a global `BytePos`, computes the local offset within the containing `SourceFile`. |
| pub fn lookup_byte_offset(&self, bpos: BytePos) -> SourceFileAndBytePos { |
| let idx = self.lookup_source_file_idx(bpos); |
| let sf = (*self.files.borrow().source_files)[idx].clone(); |
| let offset = bpos - sf.start_pos; |
| SourceFileAndBytePos {sf, pos: offset} |
| } |
| |
| /// Converts an absolute `BytePos` to a `CharPos` relative to the `SourceFile`. |
| pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos { |
| let idx = self.lookup_source_file_idx(bpos); |
| let map = &(*self.files.borrow().source_files)[idx]; |
| |
| // The number of extra bytes due to multibyte chars in the `SourceFile`. |
| let mut total_extra_bytes = 0; |
| |
| for mbc in map.multibyte_chars.iter() { |
| debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos); |
| if mbc.pos < bpos { |
| // Every character is at least one byte, so we only |
| // count the actual extra bytes. |
| total_extra_bytes += mbc.bytes as u32 - 1; |
| // We should never see a byte position in the middle of a |
| // character. |
| assert!(bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32); |
| } else { |
| break; |
| } |
| } |
| |
| assert!(map.start_pos.to_u32() + total_extra_bytes <= bpos.to_u32()); |
| CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes as usize) |
| } |
| |
| // Returns the index of the `SourceFile` (in `self.files`) that contains `pos`. |
| pub fn lookup_source_file_idx(&self, pos: BytePos) -> usize { |
| self.files.borrow().source_files.binary_search_by_key(&pos, |key| key.start_pos) |
| .unwrap_or_else(|p| p - 1) |
| } |
| |
| pub fn count_lines(&self) -> usize { |
| self.files().iter().fold(0, |a, f| a + f.count_lines()) |
| } |
| |
| |
| pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> { |
| let prev_span = self.span_extend_to_prev_str(span, "fn", true); |
| self.span_to_snippet(prev_span).map(|snippet| { |
| let len = snippet.find(|c: char| !c.is_alphanumeric() && c != '_') |
| .expect("no label after fn"); |
| prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32)) |
| }).ok() |
| } |
| |
| /// Takes the span of a type parameter in a function signature and try to generate a span for |
| /// the function name (with generics) and a new snippet for this span with the pointed type |
| /// parameter as a new local type parameter. |
| /// |
| /// For instance: |
| /// ```rust,ignore (pseudo-Rust) |
| /// // Given span |
| /// fn my_function(param: T) |
| /// // ^ Original span |
| /// |
| /// // Result |
| /// fn my_function(param: T) |
| /// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>` |
| /// ``` |
| /// |
| /// Attention: The method used is very fragile since it essentially duplicates the work of the |
| /// parser. If you need to use this function or something similar, please consider updating the |
| /// `SourceMap` functions and this function to something more robust. |
| pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> { |
| // Try to extend the span to the previous "fn" keyword to retrieve the function |
| // signature. |
| let sugg_span = self.span_extend_to_prev_str(span, "fn", false); |
| if sugg_span != span { |
| if let Ok(snippet) = self.span_to_snippet(sugg_span) { |
| // Consume the function name. |
| let mut offset = snippet.find(|c: char| !c.is_alphanumeric() && c != '_') |
| .expect("no label after fn"); |
| |
| // Consume the generics part of the function signature. |
| let mut bracket_counter = 0; |
| let mut last_char = None; |
| for c in snippet[offset..].chars() { |
| match c { |
| '<' => bracket_counter += 1, |
| '>' => bracket_counter -= 1, |
| '(' => if bracket_counter == 0 { break; } |
| _ => {} |
| } |
| offset += c.len_utf8(); |
| last_char = Some(c); |
| } |
| |
| // Adjust the suggestion span to encompass the function name with its generics. |
| let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32)); |
| |
| // Prepare the new suggested snippet to append the type parameter that triggered |
| // the error in the generics of the function signature. |
| let mut new_snippet = if last_char == Some('>') { |
| format!("{}, ", &snippet[..(offset - '>'.len_utf8())]) |
| } else { |
| format!("{}<", &snippet[..offset]) |
| }; |
| new_snippet.push_str( |
| &self.span_to_snippet(span).unwrap_or_else(|_| "T".to_string())); |
| new_snippet.push('>'); |
| |
| return Some((sugg_span, new_snippet)); |
| } |
| } |
| |
| None |
| } |
| pub fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool { |
| source_file.add_external_src( |
| || match source_file.name { |
| FileName::Real(ref name) => self.file_loader.read_file(name).ok(), |
| _ => None, |
| } |
| ) |
| } |
| pub fn call_span_if_macro(&self, sp: Span) -> Span { |
| if self.span_to_filename(sp.clone()).is_macros() { |
| let v = sp.macro_backtrace(); |
| if let Some(use_site) = v.last() { |
| return use_site.call_site; |
| } |
| } |
| sp |
| } |
| } |
| |
| #[derive(Clone)] |
| pub struct FilePathMapping { |
| mapping: Vec<(PathBuf, PathBuf)>, |
| } |
| |
| impl FilePathMapping { |
| pub fn empty() -> FilePathMapping { |
| FilePathMapping { |
| mapping: vec![] |
| } |
| } |
| |
| pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping { |
| FilePathMapping { |
| mapping, |
| } |
| } |
| |
| /// Applies any path prefix substitution as defined by the mapping. |
| /// The return value is the remapped path and a boolean indicating whether |
| /// the path was affected by the mapping. |
| pub fn map_prefix(&self, path: PathBuf) -> (PathBuf, bool) { |
| // NOTE: We are iterating over the mapping entries from last to first |
| // because entries specified later on the command line should |
| // take precedence. |
| for &(ref from, ref to) in self.mapping.iter().rev() { |
| if let Ok(rest) = path.strip_prefix(from) { |
| return (to.join(rest), true); |
| } |
| } |
| |
| (path, false) |
| } |
| } |
